Northern-based rebels in Ivory Coast are refusing to withdraw from front lines, until the government accepts a new power-sharing peace proposal. This follows renewed violence involving unidentified assailants early Friday, which left about 20 people dead in the southern commercial capital, Abidjan.

Ivorian officials had said the army and northern-based rebels were due to begin pulling back their fighters and heavy weapons on Saturday.

The two sides were also due to lift roadblocks, both in the government-held south and in the rebel-held north.

But a rebel political leader, Cisse Sendou, says the rebels are refusing to begin the pullback, until a new proposal, which rebels presented earlier this week in Abidjan is accepted.

"The process won't start today, because we gave certain conditions to be fulfilled before we start anything," he said. "And, those conditions have been given to the prime minister and Albert Tevoedjre, the U.N. envoy, and they said we should get an answer in about two days, or so."

The conditions include delegating more powers to the reconciliation prime minister, Seydou Diarra, who is a northerner.

The rebels pulled out of a power-sharing government in September, accusing President Laurent Gbagbo of keeping all the power to himself, and blocking implementation of a French-brokered January peace deal. The rebels who started their insurgency more than a year ago say they are fighting for equal rights for northern Ivorians, many of whom are now considered immigrants.

On Saturday, road blocks remained in the government-held city of Abidjan, in the south.

Security forces also carried out dozens of arrests in Abidjan's Abobo neighborhood, where many poor northerners reside.

There were also reports of shots being heard in the area, as the arrests were made.

A roadside coffee seller in Abobo, Dianne Kouame, says the situation is very tense.

"Everybody is still scared," she said. "Even this morning, we heard two shots being fired. I heard some when I was going in the taxi going to work."

The arrests follow several unexplained firefights, which took place in the early morning hours of Friday, including two in Abobo. About 20 people were killed.

Government officials said unidentified assailants had simultaneously attacked police barricades in several parts of the city, before being gunned down. The northern-based rebels say they had nothing to do with the renewed violence.

Full scale fighting ended in Ivory Coast late last year, when several thousand French peacekeepers deployed along front lines dividing the north from the south.